Audio speakers or loudspeakers are ubiquitous on many devices used by individuals, including televisions, stereo systems, computers, smart phones, and many other consumer devices. Generally speaking, an audio speaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Given its nature as a mechanical device, an audio speaker may be subject to damage caused by operation of the speaker, including overheating and/or overexcursion, in which physical components of the speaker are displaced too far a distance from a resting position. To prevent such damage from happening, speaker systems often include control systems capable of controlling audio gain, audio bandwidth, and/or other components of an audio signal to be communicated to an audio speaker.
Speaker protection techniques can reduce the input signal energy in such a way so as to protect the speaker from over-excursion and/or over-heating damage, while simultaneously minimizing the unwanted audible effects to the output signal. Conventional techniques use voltage and current sensing feedback information in order to adaptively model the speaker status and, consequently, to estimate speaker displacement and temperature. Various filtering, equalization, and amplitude scaling are then performed on the input signal to minimize its energy. Unfortunately, most of these techniques do not take into account the human audio perception aspects and consequently the resulting processed signal is audibly degraded in an uncontrollable fashion.
Shortcomings mentioned here are only representative and are included simply to highlight that a need exists for improved electrical components, particularly for audio components employed in consumer-level devices, such as mobile phones. Embodiments described herein address certain shortcomings but not necessarily each and every one described here or known in the art.